package com.astrofizzbizz.utilities;


import java.io.File;
import java.util.Hashtable;
import java.util.Enumeration;
import javax.swing.filechooser.*;

 /**
 * @author mcginnis
 *
 */
public class FileChooserFilter extends FileFilter
{
//    private static String TYPE_UNKNOWN = "Type Unknown";
//	private static String HIDDEN_FILE = "Hidden File";
 	private Hashtable<String, FileChooserFilter> filters = null;
	private String description = null;
	private String fullDescription = null;
	private boolean useExtensionsInDescription = true;
    /**
 	* Creates a file filter. If no filters are added, then all
	* files are accepted.
	*
	* @see #addExtension
	*/
	public FileChooserFilter() 
	{
		this.filters = new Hashtable<String, FileChooserFilter>();
	}
	/**
	* Creates a file filter that accepts files with the given extension.
	* Example: new ExampleFileFilter("jpg");
	 * @param extension 
	*
	* @see #addExtension
	*/
	public FileChooserFilter(String extension) 
	{
		this(extension,null);
	}
	/**
	* Creates a file filter that accepts the given file type.
	* Example: new ExampleFileFilter("jpg", "JPEG Image Images");
	*
	* Note that the "." before the extension is not needed. If
	* provided, it will be ignored.
	 * @param extension 
	 * @param description 
	*
	* @see #addExtension
	*/
	public FileChooserFilter(String extension, String description) 
	{
		this();
		if(extension!=null) addExtension(extension);
		if(description!=null) setDescription(description);
	}
	/**
	* Creates a file filter from the given string array.
	* Example: new ExampleFileFilter(String {"gif", "jpg"});
	*
	* Note that the "." before the extension is not needed adn
	* will be ignored.
	 * @param filters 
	*
	* @see #addExtension
	*/
	public FileChooserFilter(String[] filters) 
	{
		this(filters, null);
	}
	/**
	* Creates a file filter from the given string array and description.
	* Example: new ExampleFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
	*
	* Note that the "." before the extension is not needed and will be ignored.
	 * @param filters 
	 * @param description 
	*
	* @see #addExtension
	*/
	public FileChooserFilter(String[] filters, String description) 
	{
		this();
		for (int i = 0; i < filters.length; i++) 
		{
			// add filters one by one
			addExtension(filters[i]);
		}
		if(description!=null) setDescription(description);
	}
	/**
	* Return true if this file should be shown in the directory pane,
	* false if it shouldn't.
	*
	* Files that begin with "." are ignored.
	*
	* @see #getExtension
	* @see FileFilter#accepts
	*/
	public boolean accept(File f) 
	{
		if(f != null) 
		{
			if(f.isDirectory()) 
			{
				return true;
			}
			String extension = getExtension(f);
			if(extension != null && filters.get(getExtension(f)) != null) 
			{
				return true;
			};
		}
		return false;
	}
	/**
	* Return the extension portion of the file's name .
	 * @param f 
	 * @return String
	 *
	* @see #getExtension
	* @see FileFilter#accept
	*/
	public String getExtension(File f) 
	{
		if(f != null) 
		{
			String filename = f.getName();
			int i = filename.lastIndexOf('.');
			if(i>0 && i<filename.length()-1) 
			{
				return filename.substring(i+1).toLowerCase();
			};
		}
		return null;
	}
	/**
	* Adds a filetype "dot" extension to filter against.
	*
	* For example: the following code will create a filter that filters
	* out all files except those that end in ".jpg" and ".tif":
	*
	*   ExampleFileFilter filter = new ExampleFileFilter();
	*   filter.addExtension("jpg");
	*   filter.addExtension("tif");
	*
	* Note that the "." before the extension is not needed and will be ignored.
	 * @param extension 
	*/
	public void addExtension(String extension) 
	{
		if(filters == null) 
		{
			filters = new Hashtable<String, FileChooserFilter>(5);
		}
		filters.put(extension.toLowerCase(), this);
		fullDescription = null;
	}
	/**
	* Returns the human readable description of this filter. For
	* example: "JPEG and GIF Image Files (*.jpg, *.gif)"
	*
	* @see setDescription
	* @see setExtensionListInDescription
	* @see isExtensionListInDescription
	* @see FileFilter#getDescription
	*/
	@SuppressWarnings("rawtypes")
	public String getDescription() 
	{
		if(fullDescription == null) 
		{
			if(description == null || isExtensionListInDescription()) 
			{
				fullDescription = description==null ? "(" : description + " (";
				// build the description from the extension list
				Enumeration extensions = filters.keys();
				if(extensions != null) 
				{
					fullDescription += "." + (String) extensions.nextElement();
					while (extensions.hasMoreElements()) 
					{
						fullDescription += ", ." + (String) extensions.nextElement();
					}
				}
				fullDescription += ")";
			} 
			else 
			{
				fullDescription = description;
			}
		}
		return fullDescription;
	}
	/**
	* Sets the human readable description of this filter. For
	* example: filter.setDescription("Gif and JPG Images");
	 * @param description 
	*
	* @see setDescription
	* @see setExtensionListInDescription
	* @see isExtensionListInDescription
	*/
	public void setDescription(String description) 
	{
		this.description = description;
		fullDescription = null;
	}
	/**
	* Determines whether the extension list (.jpg, .gif, etc) should
	* show up in the human readable description.
	*
	* Only relevent if a description was provided in the constructor
	* or using setDescription();
	 * @param b 
	*
	* @see getDescription
	* @see setDescription
	* @see isExtensionListInDescription
	*/
	public void setExtensionListInDescription(boolean b) 
	{
		useExtensionsInDescription = b;
		fullDescription = null;
	}
	/**
	* Returns whether the extension list (.jpg, .gif, etc) should
	* show up in the human readable description.
	*
	* Only relevent if a description was provided in the constructor
	* or using setDescription();
	 * @return boolean
	*
	* @see getDescription
	* @see setDescription
	* @see setExtensionListInDescription
	*/
	public boolean isExtensionListInDescription() 
	{
		return useExtensionsInDescription;
	}
}
